1. Field of the Invention
The present invention relates to the removal of obsolete drill platforms from inland seas and ocean floors.
2. Description of Related Art
Presently, drill platforms are used in oil and gas exploration in inland seas and ocean floors. After a period of time, the platforms become obsolete because gas and oil can no longer be extracted from the sea floor and ocean floor.
Several options currently exist for the removal of drill platforms after they have become obsolete. However, these options suffer from various drawbacks. First, a crane or other lifting device may be used to remove the caissons of a drill platform that were hammered into the soft mud or sand of the ocean floor. This method has achieved only very limited success and will not work with larger caissons.
Another method is to use explosives either above or below the mud line surrounding the caisson. While this method is both quick and inexpensive, it has a drastic, negative effect on marine life. The shock waves of such explosives tend to kill sensitive marine organisms and other living creatures. Furthermore, the byproduct residue from the explosions is detrimental to marine organisms and animals in the immediate area of the explosion as well as more distant areas.
A third method of removal is for divers to use various cutting tools, such as cutting torches, high-pressure water with an abrasive assist and diamond chain saws, to remove the caissons. This method also has a variety of drawbacks. First, this type of removal is dangerous for the divers. Further, some of the abrasive assists used with a high-pressure water cutting device are not environmentally friendly. Finally, since the caissons cannot be cut below the mud line, jagged edges are left above or near the mud line which could endanger future recreational divers and any future undersea cables, pipelines or the like.
A final method is to merely leave the platforms in place or modify them so a portion of the platform remains under water for the formation of a coral reef. This method is generally unacceptable or impossible. Furthermore, the United States Federal Government has recently instituted regulations for the removal of obsolete drill platforms. These new regulations have been implemented primarily because of environmental concerns. These regulations require the owner to take responsibility for all platforms in federal waters, the owner of a platform to remove the structure 15 feet below the mud line once it has become obsolete and obtain a permit to create an artificial reef.
Accordingly, a need exists for a method for removal of obsolete drill platforms that overcomes the drawbacks of the prior art methods for removal and conforms to the new United States Federal Government regulations.